Treatment of polymeric materials



1954 c. w. SAMMONS ETAL 2,685,497

TREATMENT OF POLYMERIC MATERIALS Filed April 26, 1949 4 j 2 H i AnmKA/Eys Patented Aug. 3, 1954 UNITED STATES RATENT OFFICE TREATMENT OFPOLYMERIC MATERIALS.

Application April 26, 1949, Serial No. 89,807=

Claims priority, application Great Britain May 12, 1948 7 Claims. 1

This invention relates to improvements in the treatment of filaments oryarns of polymeric materials, and more particularly polymeric materialsof the character described in U. S. Patents Nos. 2,512,627 and2,512,632. Insaid U. S. patents there is described the production ofnitrogencontaining copolymers by condensing polyaminotria zoles obtainedaccording to U. S. Pat. Nos. 2,512,600 and 2,512,667 with polycarboxylicamides, and particularly polycarboxylic amides with terminal aminogroups, and there is further described the production of suchnitrogencontaining copolymers from a pre-iormed polycarboxylic amidewith the constituents necessary to form a polyaminotriazole, or from apreformed polyaminotriazole and the constituents necessary to form apolycarboxylic amide. In all cases the reaction to produce the finalcopolymer is carried out with the reagents in a mobile state and isstopped while the polymer'is still linear.

Generally these polymers are capable of undergoing reaction Withformaldehyde, glyoxal or. other aldehydes, for example acetaldehyde, torender the polymers insoluble. or less soluble in organic solvents suchas formic acid or phenols, and substantially infusible.

We have now found that such treatments of filaments and yarns withaldehydes may be so applied and combined with a mechanical treatment asto produce a crimped yarn. The mechanical treatment consists in analternate tensioning and relaxation of the filaments or yarns.Preferably the treatment is applied to filaments or yarns whichv havenot been cold drawn but it may be applied to filaments and yarns whichhave been incompletely cold drawn. For example, if a polymer of the typeproduced according to the prior patents referred to by condensing apreformed poly-t-amino-1.2.4-triazole with a diamine-stabilisedpolyamide is spun into filaments and the filaments, before cold drawing,are treated with aqueous formaldehyde, the formaldehyde allowed to dryon the filaments until nearly all the water is evaporated, and thefilaments are then subjected to alternate tensioning and relaxation,with each repeated removal of thetension a more and more crimped effectis produced.

This crimped chest is not produced either with a yarn composed or" asimple polyaminotriazole produced according to U. S. Pat. Nos. 2,512,600and 2,512,667, or with yarns made of a simple polyamida, Theformaldehyde can react, with both these types of'yarns, but ontensioning and 2. relaxation no crimping or substantially no crimp"- ingis produced. The maximumcrimping isobtained by using a yarn in which theweight of polyamide components in the copolymer is roughly twice theweight of polyaminotriazol'e or polyaminotriazole components. in theyarn. However, quite good crimping is obtained with other proportions ofthe components. For example, the proportions mayv be from 2 of polyamideto I of polyaminotriazole up to 1 of polyamide to 2 ofpolyaminotriazole, andfurthermore the crimping effect is observed in alower degree. in limits outside these, for example in co-poly merscontaining proportions from 5 of polyarnide to 1 of polyaminotriazole upto lof polyamide to 3 or of polyaminotriazole'. However, we prefer touse copolymers of the typedescribecl in U. 8. Patent 2,512,627 where thetotal weight of aminotriazole in the co-polyamide/aminotriazole is lessthan 50%. It may be of the order of 20-45%. All these proportions are byweight.

Generally the invention therefore comprises the treatment of filamentsor a yarn of a copolymer containing both aminotriazole and carboxylicamide units with formaldehyde or other aldehyde, followed by alternatetensioning and relaxation of the yarn until the crimping effect isproduced.

The mechanical working, involving successive tensioning and relaxation,may be carried out as a continuous process by passing yarns containingthetreated filamentsover a series of devices designed successively to.apply tension and. to relax tension. Such devices may, for example, be aseries of eccentrically mounted. rollers, the phase of the eccentricityof successive pairs of rollers being so arranged. as to. apply tensionin a run between two pairs of rollers and to relax that tension in therun between the next two pairs of rollers. Alternatively the rollers maybe alternately eccentrically mounted and concentrically mounted.Furthermore, instead of using eccentrically mounted rollers in either ofthe above arrangements, other mechanical: def vices, such aseccentrically mounted bladesmay be used, the blades having the.advantage that they permit a higher degree of drawin and hence a higherdegree of relaxation. Apparatus oi the general character described in U.S. Patents Nos. 1,898,085 and 2,033,722 maybe used for thispurpose.

Apparatus that. may be employed in carrying outgthe. process of. this,invention is shown. diagrammatically in the. accompanying drawingwherein Fig. 1 is a side elevation of the apparatus for applyingformaldehyde,

Fig. 2 is a side elevation of a device for tensioning and relaxing theyarns, and

Fig. 3 is a side elevation of another form of device for tensioning andrelaxing the yarns.

The following example illustrates the invention:

Example An unoriented yarn was melt spun from a copolymer prepared bycondensation of 10-12 parts of a diamine-stabilized polyamide ofintrinsic viscosity about O.2O.3, produced from hexamethylene diamineand adipic acid, with about 6 parts of a polyaminotriazole produced fromsebacic dihydrazide and hydrazine and also condensed to an intrinsicviscosity of the order of 0.2-0.3. The details, apart from theproportions, for producing such a copolymer are described in example 12of U. S. Patent No. 2,512,627. The melt spun yarn was then processed asfollows on the apparatus illustrated in the drawing. The yarn l wasunwound from a cheese or bobbin 2 and carried at a speed of 39 feet perminute into a 3-ft. trough 3 continuously supplied with 40% aqueousformaldehyde at C. by means of an inlet 4 and overflow 5 so that thetime of immersion was approximately seconds. The yarn was then carriedout of the trough and given a vertical run over a pulley 6 and thencedown toa hank winding machine 2', the total air run being 30-40 feet.The slightly damp hank was then allowed to stand at room temperature for5 minutes or more, and then subjected to alternate stretching andrelaxation until the desired crimp had been produced. On stretching theyarn exhibited a rubber-like elasticity but with each repeated removalof tension a more and more crinkled effect was produced until finallythe yarn was highly crimped.

One form of device for carrying out this step is shown in Fig. 2 andcomprises three driven rollers 3, 9 and It that are mountedeccentrically out of phase so that as the yarn l passes around saidrollers it will be alternately tensioned and relaxed. Another form ofdevice for carrying out this step is shown in Fig. 3 and comprises threedriven rollers ll, i2 and it, around which the yarn l passes and ofwhich rollers 5i and iii are mounted eccentrically and roller i2 ismounted concentrically.

In a similar way, other co-polyamide/aminotriazoles of the typedescribed in U. S. Pats. Nos. 2,512,827 and 2,512,632 may be subjectedto a treatment with formaldehyde in the unoriented state, oralternatively the yarns may previously be partly but not completelydrawn, the degree of crimp produced being dependent to some extent onthe degree of cold. drawing before the formaldehyde treatment. Theperiod of treatment with the formaldehyde may be reduced by raising thetemperature. In a similar manner, other aldehydes, particularly glyoxal,may be used. Furthermore, other aldehydes, such as acetaldehyde, may beemployed, but generally these other aldehydes are much less reactivethan formaldehyde and therefore do not give the crimp effect so readily.

The treatment according to the present invention may be applied toyarns, twisted or untwisted, of filaments of relatively low filamentdenier, e. g. of the order of 2 to 5, 10 or filament denier, orfilaments of relatively large denier, e. g. up to filaments of bristledimensions.

Further, the treatment may be applied to yarns, which will of course betwisted, containing staple fibres made of the polymers. Special effectsmay be obtained by treatment of mixed yarns containing staple fibres ofthe polymer together with staple fibres of other materials, for examplof cellulose acetate or other cellulose derivative or of the nylon typeof polyamide, or containing continuous filaments of the polymer andcontinuous filaments or another fibre-forming material. In the case oftreating a product, particularly a continuous filament product,containing undrawn filaments of the triazole polymer together withundrawn filaments of a nylon type of polymer, tensioning produceselongation in both types of filament, while during the relaxation periodthe triazole filaments shorten in length and produce the crimp whereasthe nylon type of filament retains its stretched length and thus appearsin loops along the yarn. By this means a very voluminous yarn may beproduced.

Having described our invention, what we desire to secure by LettersPatent is:

1. Process for the production of crimped yarns, which comprises reactingyarns, made from a linear co-polymer whose links consist of carboxylicamide and aminotriazole groups, containing lfi% by weight ofpolyaminotriazole constituents, which yarns are not completely drawn,with an aldehyde and repeatedly alternately tensioning and relaxing thematerials until a crimp is produced.

2. Process for the production of crimped yarns, which comprises reactingyarns, made from a linear co-polyrner whose links consist of carboxylicamide and aminotriazole groups, containing 16%80% by weight ofpolyaminotriazole constituents, which yarns are not completely drawn,with aqueous formaldehyde and repeatedly alternately tensioning andrelaxing the materials until a crimp is produced.

3. Process for the production of crimp-ed yarns, which comprisesreacting yarns, made from a linear co-polymer whose links consist ofcarboxylio amide and aminotriazole groups, containing 16 7 -8094; byweight of polyaininotriaaole constituents, which yarns are notcompletely drawn, with aqueous formaldehyde, permitting the materials todry until substantially all the Water is removed, and repeatedlyalternately tensioning and relaxing the materials until a crimp isproduced.

4. Process for the production of crimped yarns, which comprises reactingyarns, made from a linear co-polymer whose links consist of carboxylicamide and aminotriazole groups, containing l6%80% by wei ht ofpolyaminotriazole constituents, which yarns are not completely drawn,with aqueous formaldehyde at about 40 0., permitting the materials todry until substantially all the water is removed, and repeatedlyalternately tensicning and relaxing the materials until a crimp isproduced.

5. Process for the production of crimped yarns, which comprises treatingyarns, made from a linear co-polymer whose linlrs are carboxylic amideand aminotriazole, the polymer containing less than 50% but more than 16/3 70 by weight of aminotriazole constituents and more than 50% byweight of amide constituents, which yarns are not completely drawn, withaqueous formaldehyde, permitting the materials to dry untilsubstantially all the water is removed, and repeatedly alternatelytensioning and relaxing the materials until a crimp effect is produced.

6. Process for the production of crimped yarns, which comprises treatingyarns, made from a linear co-polymer Whose links are carboxylic amideand aminotriazole and which contains 20-45 of aminotriazole constituentsand 80-55 of carboxylic amide constituents, which yarns are notcompletely drawn, with aqueous formaldehyde, permitting the materials todry until substantially all the water is removed, and repeatedlyalternately tensioning and relaxing the materials until a crimp efiectis produced.

'7. Process for the production of crimped yarns, which comprisestreating yarns, made from a linear co-polymer whose links are carboxylicamide and aminotriazole and which contains 20-45% of aminotriazoleconstituents and 80-55% of carboxylic amide constituents, which yarnsare not completely drawn, with aqueous formaldehyde at about 4G C.,permitting the materials to dry until substantially all the Water isremoved, and repeatedly alternately tensioning' and relaxing thematerials until a crimp effect is produced.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date Dreyfus et a1 Feb. 21, 1933 Dreyfus et a1 Apr. 28, 1936 EwingJune 30, 1942 Lely Aug. 25, 1942 Highberger et al. Apr. 24, 1945 RobbinsJune 5, 1945 Thomson Feb. 1, 1949 Waltz July 26, 1949 Fisher et a1. June27, 1950 Fisher et al June 2'7, 1950 Fisher et a1 June 2'7, 1950Moncrieff June 27, 1950 FOREIGN PATENTS Country Date Great Britain Mar.14, 1941 Great Britain July 16, 1945

1. PROCESS FOR THE PRODUCTION OF CRIMPED YARNS, WHICH COMPRISES REACTING YARNS, MADE FROM A LINEAR CO-POLYMER WHOSE LINKS CONSIST OF CARBOXYLIC AMIDE AND AMINOTRIAZOLE GROUPS, CONTAINING 162/3-80% BY WEIGHT OF POLYAMINOTRIAZOLE CONSTITUENTS, WHICH YARNS ARE NOT COMPLETELY DRAWN, WITH AN ALDEHYDE AND REPEATEDLY ALTERNATELY TENSIONING AND RELAXING THE MATERIALS UNTIL A CRIMP IS PRODUCED. 